Posterior Abdominal Wall Anatomy PDF

Posterior Abdominal Wall & Lumbar & Sacral Plexus Contents of posterior abdominal wall five lumbar vertebra psoas major, iliacus, quadratus lumborum & posterior part of diaphragm fascia Nerves: Subcostal nerve, Lumbar plexus Fat vessels (aorta, IVC) and lymph nodes Fascia of the posterior abdominal...

Posterior Abdominal Wall & Lumbar & Sacral Plexus Contents of posterior abdominal wall five lumbar vertebra psoas major, iliacus, quadratus lumborum & posterior part of diaphragm fascia Nerves: Subcostal nerve, Lumbar plexus Fat vessels (aorta, IVC) and lymph nodes Fascia of the posterior abdominal wall The psoas fascia (psoas sheat) –psoas fascia medial arcuate ligament –iliac fascia Fascia of the posterior abdominal wall The quadratus lumborum fascia (anterior layer of thoracolumbar fascia) lateral arcuate lig Psoas Major Muscle  Psoas is a Greek word ‘loin’  to reach the lesser trochanter  the lumbar plexus of nerves Psoas Major Muscle O: transverse procc of lumbar v & sides of bodies of T12-L5 vert & intervertebral discs I: lesser trochanter N: Lumbar plx (ventral ramii of L1-L3 spinal nerves) Function of the psoas major Acting inferiorly with the iliacus Acting superiorly It is used to balance the trunk Ilıacus Muscle O: iliac fossa, ala of sacrum & ant sacroiliac ligs I: lesser trochanter N: femoral n (L2-L4) F: flexes the thigh, stabilizes the hip joint It is active Review of the Iliopsoas Muscle insertion main flexor muscle Gluteus maximus muscle innervation Psoas abscess Clinical importance of the Iliopsoas Muscle Kidneys,ureters, cecum, appendix, sigmoid colon, pancreas, lumbar lymp nodes and nerves of posterior abdominal wall Iliopsoas Test Quadratus Lumborum Muscle o: iliolumbar lig & iliac crest I: 12th rib & transverse procc of lumbar vrt N: T12 (subcostal) & ventral branches of L1-L4 F: fixes the 12th rib, extend & laterally flexes the vertebral column Anatomical relations of the Quadratus Lumborum Muscle kidney subcostal n iliohypogastric n ilioinguinal n ascending colon (right side) descending colon (left side) Psoas Minor Muscle 50 to 60% O: T12-L1 I: pectinate line (pecten pubis), iliopubic eminentia F: flex the vertebral column N: L1 spinal n Spinal nerves 8 CERVICAL 12 THORACIC 5 LUMBAR 5 SACRAL 1 COCCYGEAL Lumbar spinal nerves Dorsal rami muscles & skin of the back Ventral rami  pass into the psoas major muscle Lumbar plexus ventral rami of L1 through L4 nerves  lumbar plexus Branches of lumbar plexus Muscular branches: ( psoas major, quadratus lumborum, psoas minor) iliohypogastric n (L1) ilioinguinal n (L1) genitofemoral n (L1,L2) lateral femoral cutaneous n (L2,L3) femoral n (L2,L3,L4) obturator n (L2,L3,L4) accessory obturator n (L3,L4) Relations between the psoas major muscle & branches of lumbar plexus From the lateral side of the muscle : iliohypogastric n ilioinguinal n lateral femoral cutaneous n femoral n Relations between the psoas major muscle & branches of lumbar plexus genitofemoral n obturator n accessory obturator n Lumbar Plexus ventral ramus of L1 divides into two branches ventral rami of L2-L4 divide into two branches anterior branches obturator n posterior branches femoral n Iliohypogastric n (L1) kidney-quadratus lumborum Motor branches: Sensory branches: suprapubic region mons pubis Ilioinguinal n (L1) Inguinal canal Motor br sensory branches: – superomedial aspect of thigh – anterior scrotal n (M) – anterior labial n (F) inguinal canal Genitofemoral n (L1,2) Genitofemoral n (L1,2) Genital branch: – – – – – inguinal canal cremaster muscle dartos muscle scrotum mons pubis & labium majus Femoral branch: – deep to the inguinal lig – superior part of the femoral triangle GENITOFEMORAL n (genital br) GENITOFEMORAL n (femoral br) Genitofemoral nerve (L1,2) cremasteric reflex –afferent: femoral branch –efferent: genital branch Lateral femoral cutaneous nerve (L2,L3) iliacus muscle right side: caecum left side: descending colon deep to the inguinal lig skin over the anterolateral aspect of thigh until the knee joint Lateral femoral cutaneous nerve (L2,L3) MERALGIA PARESTHETICA Femoral nerve (L2,L3,L4) largest branch between the iliacus & psoas major deep to the inguinal lig Femoral nerve (L2,L3,L4) Anterior division: innervates anteromedial aspect of thigh Posterior division: motor branches and Saphen nerve – quadriceps femoris – sartorius – pectineus Femoral nerve (L2,L3,L4) Nerve to vastus medialis Femoral nerve (L2,L3,L4) Saphenous nerve – longest cutan n – adductor canal – until the first metatarsophalangeal j Saphenous nerve Obturator nerve (L2,L3,L4) obturator canal Obturator nerve (L2,L3,L4) anterior & posterior branches ant branch posterior branch pierces the obturator externus m Obturator nerve (L2,L3,L4) motor branches: adductor longus m adductor brevis m adductor magnus m (adductor part) gracilis m obturator externus m pectineus sensory branches: from the knee j N. OBTURATORIUS Accessory Obturator Nerve (L3-L4) pectineus muscle Clinical note: Femoral nerve injury extension of leg sensory lost patellar reflex Clinical note: Obturator nerve injury diminish in the adduction and lateral rotation of thigh & sensory lost If the obturator nerve is paralyzed Sacral plexus S1-S4 + lumbosacral trunk SACRAL PLEXUS Branches of sacral plexus: Nerve to quadratus femoris (L4 - S1) Nerve to obturator internus (L5 - S2) Nerve to piriformis (S1 - S2) Superior gluteal nerve (L4 - S1) Inferior gluteal nerve (L5 - S2) Posterior femoral cutaneous nerve (S1 - S3) Sciatic nerve (L4 - S3) Pudental nerve (S2-S4) PLEXUS SACRALIS PLEXUS SACRALIS N. gluteus superior N. gluteus inferior N. cutaneus femoris posterior N. pudendus N. ischiadicus – N. fibularis communis – N. tibialis Superior gluteal nerve (L4,L5,S1) gluteus medius m gluteus minimus m tensor fascia latae m from netter from Moore Clinically Oriented Anatomy Inferior gluteal n Inferior gluteal nerve (L5,S1) gluteus maximus m Posterior Femoral Cutaneous N (S1,S2,S3) Posterior Femoral Cutaneous N (S1,S2,S3) deep to the fascia lata (deep fascia of thigh) Sciatic n (L4,5 - S1,2,3) Sciatic n (L4,5 - S1,2,3) largest nerve ischial tuberosity – greater trochanter Terminal branches of the Sciatic nerve near the middle of the thigh: – Tibial n (L4,5- S1,2,3) – Common peroneal (fibular) n (L4,5S1,2) Tibial nerve(L4,5- S1,2,3) innervates the muscles the most superficial structure in the popliteal fossa between two heads of gastrocnemius Tibial nerve(L4,5- S1,2,3) in the leg: posterior tibial a. from Moore Clinically Oriented Anatomy Tibial nerve(L4,5- S1,2,3) motor branches in the thigh: – semitendinosus m – semimembranosus m – long head of biceps femoris m – Adductor magnus (hamstring part) Motor branches of Tibial n in the leg Gastrocnemius m Soleus m Plantaris m Popliteus m Flexor hallucis longus m Flexor digitorum longus m Tibialis posterior m Tibial nerve(L4,5- S1,2,3) Deep to the flexor retinaculum: – medial & lateral plantar nerves Medial plantar nerve: Lateral plantar nerve: Common Fibular (Peroneal) Nerve (L4,5- S1,2) Common Fibular (Peroneal) Nerve (L4,5S1,2) – superficial fibular (peroneal) n – deep fibular (peroneal) n Superficial Fibular (Peroneal) Nerve in the distal 1/3 of the leg: – it becomes superficial Superficial Fibular (Peroneal) Nerve Motor branches: – Fibularis longus – Fibularis brevis Sensory branches Deep Fibular (Peroneal) Nerve anterior tibial a. Deep Fibular (Peroneal) Nerve Motor branches: – – – – – – Tibialis anterior Extansor digitorum longus Extansor hallucis longus Fibularis tertius Extansor digitorum brevis Extansor hallucis brevis Sensory branches: – …………… dorsalis pedis artery Sural Nerve at the distal 1/3 of the leg: medial sural cutaneous nerve & lateral sural cutaneous nerve – small saphenous v – posterior to the lateral malleolus Sural Nerve-Small Saphenous V (vena saphena parva) The structures passing anterior to the medial malleolus:  N. saphenous  Great saphenous v The structures passing posterior to lateral malleolus :  Sural n  Small saphenous v  m. fibularis (peronous) longus  m. fibularis (peronous) brevis Nerve to Quadratus Femoris (L4-S1) gemellus inf muscle Quadratus femoris muscle Infrapriform foramen hip joint NERVE TO PRIFORMIS (S1-S2) Piriformis Nerve to obturator internus (L5 - S2) gemellus sup musc obturator internus Pudental nerve (S2-S4) Pudental nerve (S2S4)  main nerve of perineum  sensory branches: skin of the perineum & external genital org motor branches: ext anal sphincter muscle Superior gluteal nerve injury paralyzes of gluteus medius & minimus muscles when the foot is raised on the normal side, the pelvis falls on that side. gluteal gait Trendelenburg Sign + When a person has a lesion of superior gluteal nerve is asked to stand on one leg, the pelvis on the unsupported side descends, indicating that the gluteus medius and minimus on the supported side are weak or non-functional The sign is referred to clinically as a positive Trendelenburg test Sciatic n injury flexion of the leg is not lost because …………. all muscles in the leg are paralyzed. Foot droop may be occured because of the gravity sensory lost in the leg & foot except the area innervated by Common Peroneal Nerve Injury foot drop Inferior gluteal nerve injury gluteus maximus muscle The patient can not stand up from a sitting position to an standing position. patient can not ascends a stair Tibial n injury because of the lost of plantar flexion, patient can not stand on his toes